Claire Campbell expected to spend this semester studying in Shanghai. Instead, she is five days into a self-imposed quarantine at her parents' house in South Carolina.
She checks her temperature twice a day. She reads. And she waits for a family friend to slide takeout meals through the front door.
"I am going stir crazy," said Campbell, 20, a Clemson University student who returned from her study abroad trip months earlier than planned because of an outbreak of coronavirus in Wuhan, China, that has left hundreds dead and sickened thousands more. "Every day kind of melts together."
As U.S. officials impose new restrictions on travelers from China, many people who have returned to the country in recent days have hunkered down in their homes to make sure they were not carrying or spreading the disease.
Some were checking in regularly with local public health departments, taking their temperatures at regular intervals and receiving deliveries of food and water. Others were not conferring with the authorities, but choosing on their own to stay indoors, away from work, away from friends and, in some cases, away from everyone. All were counting down the days since they left China, waiting anxiously to see if symptoms develop - and to get back to normal.
"It's pretty scary," said a woman in Massachusetts whose husband and 18-month-old son have been holed up in the family's basement since returning from China last week.
The woman, a medical researcher who asked not to be named, said her family's self-imposed quarantine was a necessary step to protect others, especially since she feared her family had traveled on the same flight as a man who was later diagnosed with coronavirus.
"If people are responsible people," she said, "they are willing to do this."
Only 11 cases of coronavirus had been confirmed in the United States as of Tuesday afternoon, but the rapid spread of the disease through China has mobilized U.S. health officials. Passengers from China were being funneled into 11 airports and screened for signs of the disease.
About 200 Americans evacuated from Wuhan, the epicenter of the virus, were being quarantined on a military base. And those who had traveled in other parts of China were being asked by federal authorities to "self-quarantine" in their homes for 14 days in case symptoms emerged.
"This virus has literally only existed on planet Earth in humans for maybe two months," said Kenneth T. Cuccinelli, the acting deputy secretary of the Department of Homeland Security, who added that most people who arrived on commercial flights from China had volunteered to isolate themselves. "There is so much we don't know about it that it leads us to take additional precautions."
By Tuesday, as more Americans prepared to leave Wuhan on government evacuation flights, signs of growing concern were evident at the country's borders.
A person who landed at Los Angeles International Airport was placed under a federal quarantine order on Monday and isolated at a military base because of their travel history. A Canadian who tried to enter the United States by land was turned away because they had recently been in China. And a child who had been in quarantine in California after arriving on a previous evacuation flight was hospitalized after developing a fever and was being tested for coronavirus.
Cuccinelli said the federal government was directing air carriers to prevent most people who have traveled in China over the past few weeks from boarding flights to the United States if they are not U.S. citizens. "They won't even be on the plane," he said.
But he acknowledged that on Sunday alone, in the final hours before the federal government's quarantine rules took effect, some 5,000 U.S. citizens flew back from China.
"If we had to actually quarantine all of those people instead of rely on self-quarantines, you can just imagine what that would do to available resources. It would blow the doors off them," Cuccinelli said.
Even in states where no one has been diagnosed with the illness, precautions were put in place.
In Texas, where Joint Base San Antonio was preparing for the possibility that it would house quarantined travelers from China, military leaders scheduled a town-hall meeting for Wednesday to answer community concerns about safety. Indiana health officials said they were monitoring a resident who federal authorities had said should be quarantined at home. And in Wheeling, West Virginia, public health officials pulled someone out of an elementary school on Monday and placed them and a family member in quarantine because they had just returned from Hong Kong.
"It's going to be that time in the house together, watching a lot of movies, having family and friends bring the groceries over," said Howard Gamble, the administrator of the Wheeling-Ohio County Health Department, which is checking in with the quarantined family by phone each day to make sure they are not developing any coronavirus symptoms.
Public health officials said that the immediate threat to Americans remained low. But federal guidance for travelers has evolved quickly, creating a confusing patchwork of policies.
Starting Sunday evening, most people from other countries who had recently been in China were not being allowed into the United States, and Americans who had come from China were being asked to isolate themselves for two weeks. Some travelers, including Campbell, the Clemson student, chose to cloister themselves despite arriving several days before the rules took effect.
"I was thinking about others," said Campbell, who is majoring in international business and Chinese, and who said she had been looking forward to her study abroad trip for years. "People might not be comfortable knowing I was in China."
Evidence of public discomfort, even in the absence of any coronavirus symptoms, was widespread. In Portage, Michigan, where a family with two children had recently returned from China, school officials said rumors circulated widely on social media over the weekend about a potential health risk.
"The social media creates a certain amount of frenzy, and all of a sudden misinformation becomes fact," said Mark Bielang, the superintendent. "It really creates a problem."
But when the school district tried to assuage fears about coronavirus by releasing a statement, it referred to "one case that we are aware of," setting off more concerns. A day later, school officials released a second statement, clarifying that they were referring to a case of students traveling in China, not a case of the disease.
"We're trying to not create panic," said Bielang, who said the two children who had been in China were staying home and staying in touch with their teachers by computer.
At Princeton University, Alexander Luo said his roommates asked him to stay in a private bedroom after he got back from China. He had still not returned to class on Tuesday, despite being cleared by the university.
"Even if there wasn't a quarantine," said Luo, 18, "my roommates were concerned enough that they basically prescribed their own version of one on me."